Freight shipping containers are widely used to transport a variety of goods and products on ships, barges, railroads and over-the-highway vehicles. Container transport is very efficient since it minimizes labor costs, damage to goods and products and reduces the opportunities for pilferage and vandalism.
Containers come in different but standardized lengths. The lengths most widely used at 20, 35, 40, 45 and 48 feet. To the extent possible, the railroad cars which transport containers must be able to accommodate as many different lengths of containers as possible.
One type of container car in use is referred to as a well car since it has a container-receiving well portion or space between car railway trucks at each end. The bottom of the well is generally at about the height of the wheel axles so that when one or more containers are placed end to end in the well they provide a low profile and a low center of gravity. This makes it possible to stack a container on top to form a double stack container load. When containers are double stacked, the total length of the top layer can be the same as or considerably longer than the first layer because the top layer can extend over the ends of the well and partially over the trucks. Representative of such cars are those disclosed in U.S. Pat. Nos. 4,624,188; 4,456,413; 4,091,742; and 3,357,371. Although the railroad cars disclosed in those patents for carrying containers perform reasonably well there is a desire to have even better cars available.
The copending patent application of Jamrozy et al. Ser. No. 074,341 filed July 16, 1987, discloses an improved container well car for transporting double stacked containers up to a maximum load of 100,000 to 103,000 pounds per well. That car has seen substantial commercial use and has performed very well. However, it was not designed for, and thus is not suitable for, some of the heavier loads up to 125,000 pounds per well which the railroads and shippers now desire to have container cars carry. Additionally, it was not found feasible to simply scale up the 100,000 pounds capacity well to strengthen it to carry loads of 125,000 pounds. A need was accordingly determined to exist for a new container well car capable of handling container loads of 125,000 pounds per well.
It is accordingly a primary purpose of this invention to provide a railroad car having a well portion for carrying shipping containers characterized by structural improvements which make it easier to manufacture, strong and light weight and capable of carrying loads up to 125,000 pounds.